Brainlag PlusBalanced and unbalanced forces, F = ma, weight, inertial mass, terminal velocity and third law pairs, with the practical that tests them.
Balanced forces, no change
First law: if the resultant force on an object is zero, its velocity does not change.
Still things stay still; moving things keep the same speed in the same direction.
So a car at a steady 30 m/s on a motorway has a driving force exactly equal to the resistive forces. It is not "a bigger force forwards". That is a classic wrong answer.
The rest of this lesson and its 9 practice questions are in Plus.
Screen 1 of 5, free to read.
- 9 exam-style questions, marked as you go, each with a worked solution
- The Forces and acceleration simulation beside every question
- Anything you get wrong is saved to your flashcards